All Questions
1,203 questions
222
votes
4
answers
24k
views
Calculate SHA1 hash from binary and verify with a provided hash
I applied for a job and they asked me to write code with the following requirements:
Get a "toolbar offer" description from
http..update.utorrent.com/installoffer.php?offer=conduit. Parse the
...
- 2,209
59
votes
9
answers
14k
views
Project Euler problem 1 in Python - Multiples of 3 and 5
I'd like suggestions for optimizing this brute force solution to problem 1. The algorithm currently checks every integer between 3 and 1000. I'd like to cut as many unnecessary calls to ...
- 699
58
votes
3
answers
69k
views
Dynamic programming knapsack solution
I wrote a solution to the Knapsack problem in Python, using a bottom-up dynamic programming algorithm. It correctly computes the optimal value, given a list of items with values and weights, and a ...
- 862
27
votes
7
answers
8k
views
27
votes
2
answers
4k
views
Sudoku using 'exact cover' solver
1. Introduction
This is a solution to Weekend Challenge #3: a Sudoku solver in Python. It works by translating a Sudoku puzzle into an exact cover problem, and then solving the exact cover problem ...
- 49.9k
26
votes
5
answers
13k
views
Algorithm to transform one word to another through valid words
I have been practicing backtracking and I wanted to know how I can improve my code. For eg, I don't want to use global. Also, I am not sure if my code will work for all the cases.
...
25
votes
7
answers
30k
views
Merging Overlapping Intervals
A while back I was asked the following question in a phone interview, and to be honest it stumped me. After many long nights of rolling the problem around in my head I think I came up with a decent ...
user57594
22
votes
4
answers
21k
views
Finding all k-subset partitions
The following code generates all \$k\$-subsets of a given array. A \$k\$-subset of set \$X\$ is a partition of all the elements in \$X\$ into \$k\$ non-empty subsets.
Thus, for ...
- 411
21
votes
4
answers
44k
views
RSA algorithm implementation in Python 3
First, a reminder of the RSA algorithm and what my program implements:
Take two distinct, large primes p and q
Ideally these ...
user120313
19
votes
4
answers
5k
views
Count number of ways to paint a fence with N posts using K colors
A friend sent me this question, and I'd love somebody to review this and give his opinion.
Write an algorithm that counts the number of ways you can paint a
fence with N posts using K colors such ...
- 293
17
votes
7
answers
4k
views
Stack data structure in Python 3
I have implemented a stack in Python 3, and it works well. If anything needs to be improved, I would appreciate the criticism.
...
- 494
17
votes
2
answers
2k
views
Yandex programming contest: Alarms
I've tried to solve this challenge about 4 hours during the contest, but all my attempts exceeded the time limit. I tried to solve it with min-heap, but can't pass all the tests. How it can be solved ...
- 281
17
votes
3
answers
5k
views
Knapsack branch and bound: forward filter
I've coded branch and bound to solve the knapsack problem, and use a greedy linear relaxation to find an upper bound on a node I'm currently exploring. What I mean by this is that I first sort the ...
- 1,233
17
votes
1
answer
18k
views
Min/Max Heap implementation in Python
I'm refreshing some of my datastructures. I saw this as the perfect opportunity to get some feedback on my code.
I'm interested in:
Algorithm wise:
Is my implementation correct? (The tests say so)
...
- 1,460
17
votes
1
answer
516
views
Efficiently selecting spatially distributed weighted points
Background:
Motivation behind writing the following code is originated in the area of computer vision. More specifically – image rectification. In order to obtain rectified images, one has to find a ...
- 1,977